To see the other types of publications on this topic, follow the link: Organ culture.
Dissertations / Theses on the topic 'Organ culture'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Organ culture.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Heil, Bradley R. "DISTRACTION OSTEOGENESIS IN AN ORGAN CULTURE MODEL." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/47.
Full textAbstract:
Distraction osteogenesis (DO) is a surgical procedure in which applied strain stimulates new bone growth; however, the underlying mechanisms by which bone cells respond to load are still uncertain. An organ culture model of DO was developed and validated by using linear distraction on the femoral shafts of 5 day old Wistar rats. Two loading regimes were utilized: distracting the bones for 2 hrs on day 1 (GRP I); distracting the bones for 2 hrs on days 1, 3, and 5 (GRP II). After 1 week in culture, the bones were compared to unloaded contralateral controls and assessed for changes. Structural, dimensional, massing, micro-CT, areal, and viability properties were obtained from testing. Relative to paired controls, distracted bones demonstrated an increase in failure load (9.15% GRP I, 18.85% GRP II), increase in stiffness (31.28% GRP I, 53.21% GRP II), increases in areal and polar moments of inertia, and viability (6.21% GRP I, 13.02% GRP II). Our results suggest that DO can be modeled successfully with an organ culture, and continued use of this system will help to gain insight into the mechanisms and pathways by which distraction osteogenesis occurs.
2
Roach, H. I. "Possibilities and limitations of bone organ culture." Thesis, University of Southampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377420.
Full text
3
Wortman, Morris Rachel. "Facing the Waitlist: Visual Grammars of Organ Donation and Transplantation." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338035019.
Full text
4
Berggren, Diana. "Applications of organ culture of the mouse inner ear." Doctoral thesis, Umeå universitet, Öron- näs- och halssjukdomar, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-99333.
Full textAbstract:
The embryonic mouse inner ear was used as a model with which to study ototoxicity and tissue interactions. The inner ear anlage can be explanted and cultured in vitro from about the 12th gestational day (gd), and will differentiate parallel with the inner ear developing in vivo until a time corresponding to birth (21st gd). During this period the ovoid sac develops into the labyrinth. In the present thesis work, otic anlagen from gd 12, 13, 13.5, 15 and 16 were used. As a rule the explants were kept in culture until a time point equivalent to the 21st gd. Analyses using freeze-fracture technique and transmission electron microscopy showed that in cultured 13th gd otocysts the development of junctional complexes followed the same principal pattern as in vivo. Tight junctions develop into many strands lying parallel to the apical surface of all epithelial cells. Uncoupling of the hair cells occurs with loss of gap junctions. Some tight junctions had an aberrant appearence, with in part very thick strands and strands running at right angles to the apical surface. All aminoglycosides are potentially ototoxic. In the inner ear, outer hair cells of the organ of Corti and vestibular type I hair cells are affected by these antibiotics. The access route to the hair cells and the sites and mechanisms of action of aminoglycosides are not precisely defined. The uptake of tritiated tobramycin in 16th gd inner ears was studied. An initial rapid uptake of the drug, within 10 min, was followed by a slower accumulation, reaching a steady state after 60 min. Most of the tobramycin was bound reversibly, at least after a short period of incubation (2 h). The irreversibly bound fraction was of the same magnitude as the uptake within 10 min. Uptake took place against a concentration gradient. The otocyst can differentiate even without the statoacoustic ganglion. The interaction of the sensory epithelium with the ganglion was investigated by explanting the statoacoustic ganglion without target tissue. Twenty-five percent of the ganglions survived and had outgrowth of neurites but there was no differentiation into either the cochlear or vestibular type of neuron cells. Exposure of cultured otocysts (13 or 13.5 gd) to l-azetidine-2-carboxylic acid, a 1-proline analog that disrupts formation of collagen, resulted in retarded morphogenesis of the labyrinth and a dose- dependent derangement of the basal lamina. The expression of intermediate filaments (IFs) was analysed using monoclonal antibodies. The same IF pattem was found in cultured inner ears as in vivo. Explants were taken on 13th, 15th or 16th gd. Exposure to gentamicin, ethacrynic acid or cisplatin did not alter the IF composition. Cytokeratins (CKs) 8 and 18 were identified in all inner ear epithelia. In addition CKs 7 and 19 were visualized in the epithelia involved in maintaining endolymph homeostasis. The ganglion cells showed coexpression of CK, vimentin and neurofilaments. The elemental composition of the endolymph compartment of 16th gd inner ears cultured for 5 days was studied using energy-dispersive X-ray microanalysis. Na to K ratios characteristic of endolymph were found.S. 1-34: sammanfattning, s. 37-88: Härtill 6 uppsatser
digitalisering@umu
5
Finney, K. J. "Effects of trophic factors on intestinal mucosa in organ-culture." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382882.
Full text
6
SMITH, PETER FRANCIS. "A NOVEL ORGAN CULTURE SYSTEM FOR THE STUDY OF HEPATOTOXICITY)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188134.
Full textAbstract:
The popular use of in vitro systems for toxicity studies has increased dramatically over the past decade. Among the in vitro systems used, primary hepatocyte cultures are the most widely employed. However, in addition to being difficult to obtain and maintain in culture, the functional heterogeneity of liver is absent. Primary organ cultures of thin liver slices should overcome these limitations but the lack of a reproducible method for the rapid preparation of thin, consistent slices, combined with the difficulty in maintaining adult liver tissue in culture, has hindered their use for in vitro hepatotoxicity studies. Using a recently-developed tissue slicer, thin, consistent liver slices were prepared rapidly under minimally traumatic conditions. Subsequent culture of these slices in a novel dynamic organ culture system (DOCS) resulted in a maintenance of hepatocyte functional integrity. Slice adenosine triphosphate (ATP) and K⁺ content were maintained at in vivo levels, following an initial recovery period (2-4h) for up to 20h. Protein synthesis and secretion were linear for 20h and 16h respectively. Slices also synthesized glycogen between 4 and 12h in culture and were hormonally-responsive during the 20h culture period as demonstrated by a two-fold stimulation of glucose production by glucagon (10⁻⁷ M). Bromobenzene and allyl alcohol hepatotoxicity were studied in this system of organ culture. The slices retained their biotransformation ability for at least 6h based on maintenance of cytochrome P-450 content and O-deethylase activity. Either compound caused dose (.01-1.0 mM) and time (0-6h) dependent cytotoxicity as indicated by the loss of slice K⁺, inhibition of protein synthesis and leakage of lactate dehydrogenase (LDH). By 2h, a significant (p < 0.05) inhibition of protein synthesis was observed in allyl alcohol (.05 mM) treated slices. At 4h and 6h, significant loss of slice K('+), LDH, and inhibition of protein synthesis were evident in slices exposed to allyl alcohol (0.25 mM) or bromobenzene (0.5 mM). This toxicity was blocked by co-treatment with pyrazole (1.0 mM) or SKF 525-A (100 μM) in slices exposed to allyl alcohol or bromobenzene, respectively. Therefore, this system provides a new tool for the in vitro study of hepatotoxicity under conditions where hepatocellular functional integrity and biotransformation are maintained.
7
Coletta, Riccardo. "Manipulating growth and differentiation of embryonic intestine in organ culture." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/manipulating-growth-and-differentiation-of-embryonic-intestine-in-organ-culture(ad43b8a7-2499-4813-a1de-c46a24a079aa).html.
Full textAbstract:
Background: An ex vivo experimental strategy replicating in vivo intestinal development would provide an accessible setting to study normal and dysmorphic biology, and would be a test bed for tissue engineering. Previous studies implicated transforming growth factor β1 (TGFβ1) in postnatal gut maturation and regeneration following injury, but its potential role in intestinal development is poorly understood. I firstly hypothesised that embryonic small intestine is able to heal after physical injury. To test this idea, I aimed to create an organ culture model using explants of embryonic jejunum. I secondly hypothesised that TGFβ1 affects embryonic small intestine growth and differentiation. Accordingly, I aimed to use the same organ culture model to determine potential effects of exogenous TGFβ1.Methods. Segments of mouse embryonic jejunum were isolated by dissection and placed on semipermeable platforms. They were fed with defined, serum free, media, in some cases supplemented with TGFβ1. Growth, differentiation and healing of explants were characterized and quantified using a battery of techniques that included whole mount imaging, histology, immunostaining and RNA arrays. TGFβ1 was measured in amniotic fluid by enzyme-linked immunosorbent assay. Groups were compared by statistical tests. Results: After three days of culture, jejunal rudiments differentiated from simple tubes into a more complex structures containing smooth muscle surrounding newly formed villi. Pairs of rudiments, linked by a thread, fused and formed a continuous single lumen, as assessed by trajectories of fluorescent dextrans injected into their distal ends. Functional continuity was confirmed by spontaneous waves of peristalsis crossing the point of fusion. In vivo, TGFβ receptors I and II were detected in embryonic longitudinal smooth muscle cells and, in organ culture, exogenous TGFβ1 induced differentiation of longitudinal smooth muscle. Microarray profiling showed that TGFβ1 increased smooth muscle associated transcripts in a dose-dependent manner. TGFβ1 protein was detected in amniotic fluid at a time when the embryonic small intestine was physiologically herniated. Conclusion: Embryonic jejunal segments can fuse to form a single functional organ when aided by a mechanical manipulation. By analogy with the requirement for exogenous TGFβ1 for smooth muscle differentiation in culture, the TGFβ1 protein that I demonstrated to be present in the amniotic fluid may enhance intestinal development when it is physiologically herniated in early gestation. Future studies of embryonic intestinal cultures should add TGFβ1 in the defined media to produce a more faithful model of in vivo muscle differentiation. In future, this model could be used to test whether other growth factors enhance intestinal growth, and so pave the way to novel biological treatments for short bowel syndrome, a devastating disease with a high mortality.
8
Conklin, Brian Scott. "Viability of porcine common carotid arteries in a novel organ culture system." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/17282.
Full text
9
Shidrawi, Ray Georges. "Molecular immune aspects of coeliac disease : organ culture and peptide binding studies." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243337.
Full text
10
Watts, Susan Margaret. "Inhibition of neointima formation using the human saphenous vein organ culture model." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264064.
Full text
11
Lin, Yi-Cheng. "Novel organ culture model for a complete synovial joint : creation and application." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15850.
Full textAbstract:
Disorders affecting articular cartilage are amongst the most common problems in orthopaedics. Osteoarthritis, the end stage of the disease of articular cartilage, reduces the quality of life for tens of millions of people in the world, and has a profound impact on the economics of industrialized countries. Despite progress in articular cartilage research, the problem is still far from being defeated. Various models e.g. in vitro cartilage explants and in vivo animal models, have been established for cartilage research, but each has its own limitations. Thus, a novel ex vivo isolated joint organ culture model was developed. Bovine metatarsophalangeal joints were chosen as a suitable synovial joint because it consists of a hinge-type joint that is similar to the human knee joint, and has a large cartilage surface that provides enough space for multiple sampling in the same joint. The joints were isolated aseptically and placed into culture media. The viability of chondrocytes, glycosaminoglycan (GAG) content of cartilage matrix, cartilage morphology and water content of matrix were evaluated under different culture conditions, i.e. static, static with flowing media, and dynamic with different durations of the movement period. The model was used to investigate the effect on the sharp scalpel cartilage injury of adding serum to the culture medium by culturing the whole joint explants in serum-supplied or serum-free media. The feasibility of investigating the early phases of chondrocyte implantation in this model was also studied: circular holes of 2.5 mm diameter were created by making a pilot hole with a 2.0 mm drill followed by using a fresh 2.5 mm biopsy punch. Allogeneic isolated chondrocytes at different passages were aggregated as cell pellets and implanted in the holes to evaluate their integration ability and the response from the recipient cartilage. Results from the static model showed that, after 28 days culture, the chondrocytes were still alive with 66.5%, 80.9% and 46.9% viability in the superficial, middle and deep zones, respectively. The GAG content of the static model decreased 19.2% after the first week of culture and then lost another 15.0% during the third week. Paradoxically, at end of the 4th week the GAG level rebounded to some extent and increased 19.0% relative to the previous week. Interestingly, the cell viability of all three zones improved if the culture fluid was flowing as seen with the experiments carried out with stirred media or dynamic movement of the articular surfaces. (e.g. for the stirred media after 28 days of culture the chondrocyte viability was 80.6%, 92.4% and 70.4% for the superficial, middle and deep zones respectively.) The GAG content was maintained at a constant level in the contact area of the dynamic model, but decreased as in the media-stirred model and non-contact area of the dynamic model to a similar extent to that observed with the static model. In the injury model, the GAG content fell approximately 10.8% straight after the scalpel cut, but no further loss was observed if the joint was cultured in the serum-supplied media. In contrast, if the injured joint was cultured in the serum-free media, the GAG content continued to fall week by week and finally dropped by 41.7% at the end of the 4th week. In the chondrocyte implantation model, the majority of the host chondrocytes around the circular defect were alive (78.5 % viability). Viewed from the surface, the dead cells were all within 20 μm from the cut edge. The implanted chondrocytes, which were aggregated as cell pellets, began to transform their shapes and spread to the surrounding surface of the recipient cartilage, but did not appear to integrate with the host tissue during the first 2 weeks of culture. The results supported the validity of this ex vivo joint model and demonstrated that the chondrocytes subjected to flow of the media or dynamic loads survived well over a 4 week period. Of importance was the finding that there was no measured loss of the matrix GAG content when the joints were under dynamic load compared to all of the non-loaded conditions. This whole joint model could be of value in providing a more natural and controllable platform where research involving the normal processes or pathologic mechanisms of articular cartilage can be investigated, as well as the early response to newly developed pharmacological agents and cartilage tissue engineering constructs.
12
Söderpalm, Annika. "Photoreceptor development and degeneration in retinal organ culture Effects of neurotrophic factors /." [S.l. : s.n.], 1999. http://catalog.hathitrust.org/api/volumes/oclc/44519577.html.
Full text
13
Tronshaug, Hans Jacob Høyem. ""With rare diligence and accuracy" : the organ building of Peter Adolph Albrechtsen in the context of nineteenth-century Danish/Norvegian organ culture /." Göteborg : Göteborgs Universitet, 2001. http://catalogue.bnf.fr/ark:/12148/cb390003593.
Full text
14
Davis, Nathan Peter. "Axial stretch as a means of lengthening arteries : an investigation in organ culture." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17645.
Full text
15
Anderton, T. "Pathogenesis of Bordetella bronchiseptica infection in canine respiratory tract air interface organ culture." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596103.
Full textAbstract:
Bordetella pertussis and Bordetella parapertussis cause whooping cough in children and Bordetella bronchiseptica causes acute tracheobronchitis in dogs, commonly called kennel cough. Study of the molecular basis for Bordetella pathogenesis is hampered by the lack of infection models that use these pathogens in their natural hosts. The study of whooping cough is restricted by the exclusive infection of humans by B.pertussis, and kennel cough in dogs is limited by the difficulties associated with the use of dogs experimentally. Here I describe the development of a novel, physiologically relevant system for the maintenance of canine trachea at an air interface in vitro and its use for studying the pathogenesis of B. bronchiseptica. Wild-type B. bronchiseptica infection of the organ culture system mimics early in vivo events in that bacteria adhere to cilia, mucus production and ciliostasis are induced, and ciliated cells are damaged. Thus the model provides a physiologically relevant in vitro method for studying B.bronchiseptica pathogenesis. This model was utilised to probe the molecular basis for these events. B.bronchiseptica mutants deficient in the two-component regulatory system Bvg, filamentous haemagglutinin (FHA) or fimbriae (FIM) do not adhere to the organ culture model and do not induce pathology. Thus the bvg locus and more specifically the bvg-regulated factors, FHA and FIM are necessary for the attachment of bacteria to canine cilia, and this attachment may be necessary for the induction of subsequent pathology. A role for dermonecrotic toxin is also implicated in the induction of ciliostasis in canine trachea. The determination of the induction of cytokine expression by canine tissue in response to B.bronchiseptica infection was attempted but was unsuccessful. The significance of these findings in relation to whooping cough disease is discussed.
16
Nunes, Sandro Filipe Fernandes. "Influenza A infection dynamics in an Ex vivo organ culture of pig trachea." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609311.
Full text
17
Sasaki, Kaori. "Politicised culture, culturalised life and death : the Japanese organ transplantation and brain death debates." Thesis, Lancaster University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441371.
Full text
18
Leung, Theresa. "Cellular and tissue responses to implant materials : development of a novel organ culture model." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285839.
Full text
19
Palmer, Marion Elizabeth. "The significance of oxidative damage in the organ culture of early placental chorionic villi." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627203.
Full text
20
Gazes, Seth Brian. "Computer controlled device to independently control flow waveform parameters during organ culture and biomechanical testing of mouse carotid arteries." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31812.
Full textAbstract:
Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Rudy Gleason; Committee Member: Raymond Vito; Committee Member: W. Robert Taylor. Part of the SMARTech Electronic Thesis and Dissertation Collection.
21
Wu, Xiaohong. "Development of a mouse calvarial defect model for evaluation of biomaterials : an organ culture study." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506280.
Full textAbstract:
Mouse calvarial organ cultures have been widely utilized for investigating the biologic behaviour of intramembranous bones. This technique can be used to analyze bone both at the tissue and at the cellular level. It also has the ability to isolate local effects from systemic factors. The aim of this study was to establish a mouse calvarial critical size defect (CSD) model for evaluation of biomaterials in vitro.
22
Chan, Kit-ying, and 陳潔瑩. "Development of whole disc organ culture system and acellular disc scaffold for intervertebral disc engineering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45600077.
Full text
23
Lall, Sonia. "Studies in organ culture and the development of organogenic potential in Alnus, Sorbus and Prunus." Thesis, University of East London, 2000. http://roar.uel.ac.uk/3586/.
Full textAbstract:
Micropropagation was investigated in order to develop protocols for rapid mass production of shoots ofSorbus aucuparia and Alnus glutinosa. Removal of apical dominance either physically by pruning the plantlets or chemically by using anti-auxins TIB A (2,3,5-triiodobenzoic acid) and NPA (1-naphthylphthalamic acid) was investigated. There was a 6-fold increase in the number of rooting-ready shoots of S. aucuparia produced by the pruning of plantlets grown in vitro. A. glutinosa however, needed more drastic measures to remove apical dominance and block the endogenous auxin transport. Incorporation of TIBA (3 μm) in the medium produced an initial 8- fold increase in the number of shoots. However, repeated subculture of shoots of Alnus on TIBA containing medium proved detrimental to shoot multiplication. There was 100% rooting of shoots of S. aucuparia on agar solidified medium. The auxin: cytokinin ratio of the multiplication medium played an important role in the rooting ability of shoots. A. glutinosa also had 100% rooting on agar solidified medium. Plants were acclimatised in Baumgartner vessels before transferring to soil. There was 100% rooting and survival of the shoots of A. glutinosa both after transfer to Baumgartner vessels and subsequent transfer to soil. In S. aucuparia the survival rates in Baumgartner vessels was 70% and after transfer to soil was 65%. Direct somatic embryogenesis from zygotic tissue of both S. aucuparia and A. glutinosa was achieved. Embryos of S. aucuparia were produced on medium containing MS salts and vitamins supplemented with 1 μM BAP, 1 μM kinetin, 0.5 μM NAA, 250 mg/L L-glutamine and 500 mg/L casein hydrolysate. A. glutinosa embryos were obtained on medium containing salts and vitamins of Driver and Kuniyuki (1984) supplemented with 3 μM BAP. No auxin was required. Adventitous shoot regeneration from leaves of S.aucuparia was also achieved at a frequency of 40% on medium containing MS salts and vitamins supplemented with 10 μM TDZ and 1 μM NAA. A method for chromosome doubling of S. aucuparia using 15 uM pronamide to treat shoot tips immersed in a semi-solid medium was developed. After 14 days of treatment, 86.5% treated shoots survived and there was 44.5% chromosome doubling of the survivors. The tetraploid shoot had a higher rate of multiplication than the diploid shoots. The involvement of extracellular proteins in direct somatic embryogenesis of Prunus 'Colt' was studied. Changes in the expression of proteins were observed from the first day of transferring the tissue to embryo induction medium. Most changes were seen on the days 28 and 35 when the embryos became visible.
24
Okano, Junko. "Transforming growth factor beta2 promotes the formation of the mouse cochleovestibular ganglion in organ culture." Kyoto University, 2006. http://hdl.handle.net/2433/143848.
Full text
25
Lee, Bee Eng Adeline Media Film & Theatre UNSW. "Organ donation and anti-littering campaigns: a comparative study of Australia and Singapore." Awarded by:University of New South Wales. Media, Film and Theatre, 2005. http://handle.unsw.edu.au/1959.4/27211.
Full textAbstract:
Current literature on public communication campaigns suggests that challenges and problems remain, even though generally the effectiveness of campaigns has increased in the past years. Challenges and problems are issue-specific and efforts put into influencing particular social behaviours through public communication campaigns have not been significantly successful. Although public communication campaigns are a popular method employed to influence social behaviours in many societies, campaign strategies inadequately consider the impact of cultural elements on social behaviours. The disappointing results through the use of campaigns are exacerbated by the difficulties faced in translating research observations to appropriate campaign strategies. In view of current challenges, this research examines public communication campaigns. Two main variables shaped this research ??? ???identity??? and ???culture???. The research postulated that a person???s identity influences his or her behaviour. It also argued that culture would impact on behaviour. The theoretical orientation drew on interpretivist perspectives. Using a comparative cross-cultural method, this research nominated the issues of organ donation and waste disposal behaviours in public places and the countries of Australia and Singapore for empirical study. Focus group research was employed. A total of sixteen focus groups were conducted ??? eight groups on organ donation (four in Sydney, Australia and four in Singapore) and eight groups on waste disposal behaviours (four in Sydney, Australia and four in Singapore). In line with the theoretical orientation, ???grounded theory??? was used to analyse the focus group transcripts. It is argued that a person???s decision to organ donation or waste disposal behaviour was intimately related to his or her identity. Cultural elements are critical constituents of identity. This is to say, cultural values, beliefs and attitudes have significant impact on social behaviours. These intricacies were made apparent when each issue was seen in the national contexts of Australia and Singapore. This research concludes that issues of identity can partly explain the type of decision a person makes about organ donation, and the kind of waste disposal behaviour a person enacts. It also argues that the effectiveness of campaign strategies can potentially be enhanced, if the strategies are responsive to people???s identities.
26
Andersson, Patric, Jeanette Henrysson, and Katarina Johannson. "Att fatta beslut i organdonationsfrågan – Vad påverkar?" Thesis, Halmstad University, School of Social and Health Sciences (HOS), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-560.
Full textAbstract:
There is a shortage of organs available for donation worldwide. There have been several campaigns to try to increase the numbers of registrered donors. The topic has been brought to the forefront but more work is still needed to distribute information to the public.
The aim of this literature review was to examine what influences people in their decision to donate their organs or not, and what role nurses play in providing the most current information available. The study found that there was several different reasons given for not donating their organs. A great number of people were convinced that their religion was against organ donation. The level of knowledge about organ donation and ethnoculural background were major factors when making the decision to register as an organ donar. Only through making more information available in different languages, educating healthcare workers about culural and religions differences can the numbers of registrated donors increase.
27
Hashemi, Elham. "Precision-cut liver slices as a system for studying xenobiotic metabolism." Thesis, University of Surrey, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326474.
Full text
28
Umez-Eronini, Oparaku Nkem. "Evaluation of polyHIPE as a scaffold for bladder tissue engineering in a three dimensional organ culture model." Thesis, University of Newcastle upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419990.
Full text
29
Taura, Akiko. "Recovery of hair cell function after damage induced by gentamicin in organ culture of rat vestibular maculae." Kyoto University, 2007. http://hdl.handle.net/2433/135651.
Full text
30
Zhang, Pu. "Human ovarian follicles and oocytes : collection, cryopreservation, culture and gene expression /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-281-0/.
Full text
31
Paoli, Roberto. "Cell culture interfaces for different organ-on-chip applications: from photolithography to rapid-prototyping techniques with sensor embedding." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668376.
Full textAbstract:
Despite the last 60 years have seen major advances in many scientific and technological inputs of drug Research and Development, the number of new molecules hitting the market per billion US dollars of R&D spending has been declined steadily during the same period. The current scenario highlights the need for new research tools to enable reduce costly animal and clinical trials while providing a better prediction about drug efficacy and security in humans
A recent emerging approach to improve the current models is emerging from the field of microfluidics, which studies systems that process or manipulate tiny amounts of fluids using channels with dimensions of tens to hundreds of micrometers. Combining microfluidics with cell culture, scientists gave rise to a new field named “Organ-on-chip” (OOC). Microfluidic OOCs are advanced platforms designed to mimic physiological structures and continuous flow conditions, thus allowing the culture of cells in a friendlier microenvironment.
This thesis, titled “Cell culture interfaces for different organ-on-chip applications: from photolithography to rapid-prototyping techniques with sensor embedding”, aims to design, simulate and test new OOC devices to reproduce cell culture interface under flow conditions. The work has a focus on the exploration of novel fabrication techniques which enable rapid prototyping of OOC devices, reducing costs, time and human labor associated to the fabrication process. The final objective is to demonstrate the viability of the devices as research tools for biological problems, applying them to the tubular kidney and the blood brain barrier (BBB).
To achieve the objective, at least three device version have been developed: 1) OOCv1, fabricated by multilayer PDMS soft lithography; 2) OOCv2, fabricated in thermoplastic by layered object manufacturing using both a vinyl cutter and a laser cutter, integrating standard fluidic connectors alone (OOCv2.1) or together with embedded electrodes (OOCv2.2); 3) OOCv3 using a mixed technique of laser cut and 3D printing by stereolithography. All devices are fabricated using biocompatible materials with high optical quality and an embedded commercial membrane.
The biological experiments with renal tubular epithelial cells, realized on OOCv1 and OOCv2.1 devices, demonstrated the viability of the device for culturing cells under flow conditions. The study realized on fatty acid oxidation and accumulation in cells exposed to physiological and diabetogenic oscillating levels of glucose suggest a possible positive role of shear stress in activation of fatty acid metabolism. The studies were performed using a compact experimental unit with embedded flow control which reduce significatively the complexity and cost of the fluidic experimental setup.
The biological experiments on the BBB confirmed viability of OOCv2.1 and OOCv2.2 for compartmentalized co-culturing of endothelial cells and pericytes. The formation and recovery of the barrier after disruptive treatment has been assessed using different techniques, including immunostaining, fluorescence and live phase contrast imaging, and electrical impedance spectroscopy. The repeatability of measurements using electrodes was verified. A model to classify measurements from different timepoints has been developed, resulting in accuracy of 100% in learning and 90% in testing case. Results are confirmed by imaging data, which also suggest a critical role of pericytes in the development, maintenance, and regulation of BBB, in accordance with the literature.En los últimos años está emergiendo una nueva propuesta para mejorar los modelos actuales en el estudio de nuevos fármacos. Mediante la fusión de cultivos celulares y microfluídica ha nacido un nuevo campo de aplicación denominado “Órgano-en-un-chip” (OOC), donde se recrea un entorno fisiológico capaz de reproducir unidades funcionales mínimas de diversos órganos del cuerpo humano. Un elemento importante para el desarrollo de dispositivos OOC es la reproducción de zonas de interacción entre varios tejidos formados por diferentes tipos celulares. Esta tesis, titulada “Interfaces de cultivo celular para diferentes aplicaciones de OOC: desde fotolitografía a técnicas de prototipado rápido con inclusión de sensores”, tiene como objetivo el diseño, simulación y evaluación de dispositivos OOC capaces de reproducir superficies de contacto de tejidos contiguos expuestos a flujo. El trabajo está enfocado a la exploración de nuevas técnicas de fabricación que permitan el prototipado rápido de dispositivos OOC, reduciendo costes, tiempo y mano de obra asociada a dicha fabricación. El objetivo final es demostrar la utilidad de los dispositivos como herramientas de investigación para problemas biológicos, aplicándolos en esta tesis al estudio del túbulo renal y de la barrera hematoencefálica. Para ello se han fabricado tres versiones de dispositivos: 1) OOCv1 fabricado por litografía suave en múltiples capas de PDMS; 2) OOCv2 fabricado con cortadora de vinilo y cortadora láser en múltiples capas de materiales termoplásticos y con electrodos integrados en la versión OOCv2.2; 3) OOCv3 fabricado mediante impresión 3D por esterolitografía. Todos los dispositivos están hechos de materiales biocompatibles de alta calidad óptica, con conectores fluídicos y una membrana comercial integrada. Los experimentos biológicos sobre túbulo renal, realizados en los dispositivos OOCv1 y OOCv2, han demostrado la viabilidad de los dispositivos, integrados con un sistema de flujo, para estudios de la metabolización de ácidos grasos en el riñón relacionados con condiciones diabetogénicas. Los experimentos biológicos sobre la barrera hematoencefálica han confirmado la viabilidad de OOCv2 para el cocultivo compartimentado de células endoteliales de cerebro y pericitos. La integración de electrodos en el OOCv2.2 ha demostrado ser una técnica fiable para la medición de la integridad de barreras biológicas de modo no-invasivo, libre de etiqueta (“label-free”), y a tiempo real gracias a la espectroscopía de impedancia.
32
Essaouiba, Amal. "Development of a liver-pancreas in vitro model using microfluidic organ-on-chip technologies." Thesis, Compiègne, 2020. http://www.theses.fr/2020COMP2573.
Full textAbstract:
Le diabète mellitus, également désigné comme la maladie du siècle, est une pathologie mortelle qui affecte le système endocrinien. Les mécanismes liés à la rupture de la boucle de rétroaction, qui régule le métabolisme et induit le diabète, ne sont pas entièrement connus. La compréhension des mécanismes d'action de l'insuline est donc essentielle pour le développement de stratégies thérapeutiques efficaces afin du lutter contre cette maladie. Par conséquent, il est impératif de trouver un modèle robuste et fiable, capable de surmonter les limites de la culture cellulaire traditionnelle en 2D et de l'expérimentation animale, pour la recherche sur le diabète. L'objectif de cette thèse est de développer un nouveau modèle de co‐culture foie‐pancréas en utilisant des systèmes microphysiologiques avancés (MPs) afin d’aborder plus efficacement le mécanisme impliqué dans la régulation endocrinienne hépatique et pancréatique. Ce travail met en évidence la capacité des systèmes multi‐organes sur puce qui combinent la compartimentation avancée des cellules en 3D, la microfluidique et la technologie des cellules souches pluripotentes induites (iPSC), pour atteindre une complexité biologique élevée et des fonctions rarement reproduites par une seule de ces technologies d’ingénierie tissulaireDiabetes mellitus (DM) or the so called disease of the century is a life threatening dysfunction that affects the endocrine system. The mechanisms underlying the break in the feedback loop that regulates the metabolism and the consequent diabetes induction are not fully known. Understanding the mechanisms of insulin action is therefore crucial for the further development of effective therapeutic strategies to combat DM. Accordingly, it is imperative to find a robust and reliable model for diabetes research able to overcome the limitations of traditional 2D in vitro cell culture and animal experimentation. The aim of this thesis is to develop a new liver‐pancreas co‐culture model using advanced microphysiological systems (MPs) to tackle more effectively the mechanism involving the hepatic and pancreatic endocrine regulation. This work highlights the power of multi organ‐on‐chip systems that combines the advanced 3D‐cell compartmentalization, microfluidics and induced pluripotent stem cells (iPSC) technology to achieve a high biological complexity and functions that are rarely reproduced by only one of these tissue engineering technologies
33
Putoczki, Tracy Lynn. "A study of the efficacy of organ cultures to examine wood formation in Pinus radiata D. Don." Thesis, University of Canterbury. Biological Sciences, 2006. http://hdl.handle.net/10092/917.
Full textAbstract:
Pinus radiata D. Don is an economically important plantation species to New Zealand that is susceptible to the wood quality flaw 'intra-ring checking'. Intra-ring checking is a term used to describe radial fractures that can occur in the earlywood portion of a growth ring, altering the appearance and resilience of the wood, thereby decreasing its economic value. This thesis presents a study that was part of a broad, ongoing collaborative investigation directed at understanding wood quality issues, with the long term goal of enhancement of future radiata pine crops. These investigations are funded by the Wood Quality Initiative Ltd., and involve basic science, field trials and engineering studies related to intra-ring checking. Specifically, the present study was designed to establish the effects of the mineral nutrients boron, calcium and magnesium on wood formation, to determine whether they are associated with intra-ring checking. This research was carried out in three stages. Firstly, the ultra-structural and biochemical properties of wood with intra-ring checking were examined to determine if specific features of the cell wall were associated with the incidence of intra-ring checks. Electron microscopy techniques revealed that the CML/S1 region of the cell wall often showed a decrease in CML lignin staining and S1 striations in wood with intra-ring checks. However, Klason and acetyl bromide assays did not show a change in lignin content. In order to understand how changes in the CML/S1 region of the cell wall may occur, methods were required that would allow for the observation of wood formation in a controlled environment. In the second stage of this study, an organ culture technique was successfully developed to allow for the growth of radiata pine cambial tissue, sandwiched between phloem and xylem, on a defined nutrient medium. This nutrient medium was manipulated, using ion-binding resins, to control the amount of boron, calcium and magnesium available to the growing tissues, to determine if variations in wood formation could be induced. In the final stage of this research, an extensive comparative examination of different techniques that could be used for the observation and measurement of selected wood properties was undertaken, in order to determine the efficacy of the organ cultures to study wood formation in an altered nutrient environment. Wood properties were examined for various stages of xylogenesis, beginning with cell division and expansion, followed by cell wall deposition, and lastly with the onset of lignification in order to define the success of the culture technique. Electron microscopy investigations suggested that in the presence of very little boron the CML/S1 wall showed darker striation deposits, while an increase in calcium availability, resulted in a more defined CML/S1/S2 wall region compared to the controls. Further examination of the cell walls suggested that pectin esterification and possibly lignification could also be increased by limited boron availability. However, in many of the observed and measured parameters of wood properties, a great deal of complex 'between-tree' and 'within-culture' variation was observed. The results show that elucidation of the association between nutrient availability and the incidence of intra-ring checking can not be established from this organ culture study. In a concurrent study, the preliminary investigation of arabinogalactan-proteins (AGPs) in radiata pine was undertaken. Radiata pine AGPs were positioned in the compound middle lamella of xylem cells, suggesting potential roles in cell-cell adhesion or cell-cell signalling. For the first time, radiata pine AGPs were isolated and characterized in terms of their protein and carbohydrate composition, both of which yielded features typical of AGPs in other plant species. Unique to radiata pine AGPs was the presence of a large proportion of 5-linked arabinose. While the precise function(s) of AGPs are unknown, the results obtained in this research have established a basis for further investigation into the potential for their involvement in wood formation. Overall, new tools have been established to facilitate future research on radiata pine, a commercially important species, and novel results have been obtained concerning the mechanisms of wood formation therein.
34
Candito, Antonio. "Modelling, simulation and characterization of epithelial cell culture biochip." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8483/.
Full textAbstract:
A microfluidic Organ-on-Chip has been developed for monitoring the epithelial cells monolayer.
Equivalent circuit Model was used to determine the electrical properties from the impedance spectra of the epithelial cells monolayer.
Black platinum on platinum electrodes was electrochemically deposited onto the surface of electrodes to reduce the influence of the electrical double layer on the impedance measurements.
Measurements of impedance with an Impedance Analyzer were done to validate the equivalent circuit model and the decrease of the double layer effect.
A Lock-in Amplifier was designed to measure the impedance.
35
Song, Miyeoun. "Organ and primary culture of medaka (Oryzias latipes) testis: Test systems for the analysis of cell proliferation and differentiation." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1059039500031-89370.
Full textAbstract:
In cultured medaka testis fragments, cells remained viable for the entire culture period (17h), and spermatids that developed from spermatocytes were viable and motile. Primary cultures were characterized over a period of two days with respect to cell viability and the distribution of adherent and suspended cells. These two cell populations were maintained in dynamic equilibrium in vitro for several days. Proliferating cells were predominant among clusters of suspended cells, as determined by BrdU labeling, and CFSE and propidium iodide PI labeling. Based on cytological criteria, the proliferating cells were mostly spermatogonia and possibly also preleptotene spermatocytes. Differentiation of spermatocytes into spermatids or spermatozoa was also observed, mainly among the suspended cells. These results suggest that the organ and primary culture systems are suitable systems for studying the effects of substances that interfere with spermatogenesis in the medaka, a model vertebrate. The organ and primary culture systems were used to analyze the effects of a synthetic estrogen, EE2, on cell proliferation in medaka testis. Both organ and primary culture were suitable for this purpose consistently small concentrations (0.01 and 1 nM) of EE2 stimulated cell proliferation slightly, while higher concentrations (100 nM) had an inhibitory effect. To investigate the effect of phytoestrogens on cell proliferation in spermatogenesis, selected flavonoids [genistein (1, 10, 100 µg/ml), quercetin (0.01, 1, 100 µM), and 8-prenylnarigenin (0.001, 0.1, 1, 10 µM)] were added to medaka testis primary cultures. Genistein and quercetin inhibited cell proliferation in the cultures while 8-prenylnarigenin had no effect. In a second series of experiments the addition of genistein (10 µg/ml) to primary cultures significantly inhibited both cell proliferation and cell differentiation as determined by flow cytometry using CFSE/PI labeling.
36
Tsilingiri, Aikaterini. "A novel organ culture model for polarized stimulation of human intestinal mucosa : probiotics and postbiotics in health and disease." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=203945.
Full textAbstract:
As the use of probiotics and postbiotics is increasingly gaining ground in the past decade, the possibility of using bacterial strains with postbiotic activity to restore homeostasis in pathologic conditions such as IBD is extensively debated. However, clinical data as far as induction of remission is concerned has not been encouraging so far, while researchers observe that only a small number of treatments which seem promising on in vitro or mouse models translate to significant clinical benefit. This could mean that the models used so far to test potential treatments are not an accurate representation of the human intestine's rather complex micro-environment, and thus there is a need for the development of more relevant models. In this thesis, a novel organ culture model for polarized stimulation of intestinal mucosa is described. In the intestine, apical and basolateral challenge of the mucosal layer can elicit completely different results, and this is one of the issues addressed in this work. First of all, we show that it is possible to keep human intestinal mucosa in polarized culture for at least 24 hours, provided the explants are cultured in an atmosphere that is rich in oxygen. Polarized challenge is achieved by mechanical means, namely by attaching a cave plastic cylinder on the apical side of the mucosal layer, in order to confine the stimuli. We examine the impact of the cylinder and the surgical glue used to attach it on tissue morphology and survival, and show that there is no negative impact. Once optimized, this experimental set-up is used to challenge explants with pathogenic and probiotic bacteria alike and evaluate the immune response. On this model we are able to mimic a classical pathogen infection using a highly invasive Salmonella enterica serovar typhimurium strain, FB62. The response of the tissue to the pathogen was monitored by assessing the phenotype of explants after culture, while cytoine secretion profiles of the tissue were also studied. Salmonella challenge led to a damaged explant phenotype, upregulation of TNF-α and downregulation of IL-10. This response was abolished in the presence of an antiinflammatory postbiotic component, namely culture supernatant of the probiotic Lactobacillus paracasei. Moreover, as far as challenge with pathogens is concerned, we use this novel system to examine the mechanism of Shigella induced apoptosis of epithelial cells. Importantly, no animal models are available for the study of Shigella infection, as these 18 bacteria are poorly virulent in rodents. Thus, in an effort to study the involvement of Gadd45a in the apoptotic route triggered by Shigella on intestinal epitelial cells, HeLa cells, which are however a poor model for an intestinal pathogen were used. Gadd45a participates in the responses to a variety of DNA damaging agents and interacts with proteins such as Cdc2, PCNA and p21. In this work, the authors showed that after infection of HeLa cells with Shigella, Gadd45a is involved in the induction of the apoptotic process. The data was confirmed in a more relevant setting, by applying Shigella on human intestinal mucosa. Finally, we use the novel organ culture platform to test three different strains thought to exert probiotic actions. Surprisingly, we show that this is not the case, and the three strains can exert different activities even on healthy tissue. More specifically, Lactobacillus paracasei and Lactobacillus rhamnosus GG did not significantly alter the phenotype or cytokine secretion profiles of healthy explants, but challenge with Lactobacillus plantarum resulted in a detrimental effect. Of note, all three strains were detrimental for IBD explants when administered as live bacteria, even though one of the strains (L. paracasei) had previously been found to exert a prophylactic effect in a mouse model of colitis. On the contrary, we show that a potent postbiotic (L. paracasei culture supernatant) is able to ameliorate overt inflammation on both ulcerative colitis and Crohn's disease tissues as attested by cytokine secretion profiles of challenged explants. In conclusion, this work introduces a valid alternative system on which to study the interaction of various components (bacterial, pharmacological, and others) with the human intestinal mucosa.
37
Middlebrook, Aaron J. "Nicotine and TNF alpha, modulators of T cell signaling-effects on T cell development in fetal thymus organ culture." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280628.
Full textAbstract:
T cell development is regulated by signals generated in the interactions between developing thymocytes and the thymic stroma. Using fetal thymus organ culture (FTOC) as a model of T cell development, we investigated the ability of two potent signal modulators to influence this process. These studies show that both nicotine and tumor necrosis factor-alpha have the ability to influence T cell receptor (TCR) signaling and the maturational capacity of treated cultures. FTOC treated with low concentrations of nicotine produced more immature T cells and fewer mature T cells. These expanded populations of cells also expressed CD69, CD95 (FAS) and elevated levels of recombinase activating genes (RAG). This phenotype reflects the fact that these cells have received a positive selection signal, are for apoptosis and are likely attempting secondary TCR rearrangements. Nicotine effects were partially blocked by the nicotinic antagonist, d-tubocurarine. Furthermore, d-tubocurarine alone blocked the development of T cells entirely, suggesting the presence of an endogenous ligand that may engage nicotinic acetylcholine receptors and regulate normal thymopoeisis. These observations underscore the linkage between the nervous and the immune systems, not only in terms of shared resources, but also in terms of direct interactions between these two systems. In another study we used FTOC and an associated in vitro Type 1 diabetes mellitus model to reconcile the role of TNF-alpha in thymopoiesis with its role in diabetes. Our data indicate that thymocytes from NOD FTOC express lower levels of TNF receptors and produce more TNF-alpha compared to non-diabetic C57BL/6 (B6) FTOC. Neutralization of endogenous TNF-alpha in NOD FTOC with a soluble TNF receptor (sTNF R1) rescued insulin production in our in vitro diabetes model. NOD FTOC treated with TNF-alpha produced greater numbers of mature T cells and a higher percentage of cells expressing CD95L (Fas ligand). Treatment with sTNF R1 had the opposite effect. TNF-alpha's known ability to attenuate TCR signaling coupled with these observations suggest that its overproduction in these animals may be driving T cells to maturity, altering the process of negative selection and ultimately enhancing the survival of potentially diabetogenic T cells resulting in disease susceptibility in these animals.
38
Krammer, Thibault. "Développement d'un réseau microvasculaire sur puce microfluidique pour la reconstruction tissulaire." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV044.
Full textAbstract:
L’ingénierie tissulaire vise à développer in vitro des tissus fonctionnels ou des organes afin de fournir des plateformes de tests de médicaments ou des tissus transplantables et améliorer les traitements fournis aux patients. Cependant, les constructions tissulaires physiologiques développées à ce jour n’intègrent pas un réseau vasculaire perfusable. In vivo, le réseau vasculaire approvisionne les cellules de l’organisme en oxygène et nutriments et évacue les déchets cellulaires et le dioxyde de carbone. Il possède également un rôle prépondérant dans le maintien de l’homéostasie des organes. L’approvisionnement des cellules s’effectue au niveau des capillaires sanguins : vaisseaux creux dont la paroi est uniquement composée d’une couche de cellules endothéliales. Le réseau de capillaires sanguins est un réseau dense perfusant l’ensemble des tissus de l’organisme. De par la limite de diffusion de l’oxygène dans les tissus, chaque cellule est située au maximum à 200 µm d’un capillaire. Les difficultés de construction d’un réseau de capillaires sanguins perfusable et d’intégration au sein de constructions tissulaires limitent le développement de tissus physiologiques épais.Une technique innovante de développement d’un réseau microvasculaire à l’intérieur d’une construction épaisse est présentée dans cette thèse. Cette technique consiste en l’assemblage de micro-unités tissulaires sphériques au sein d’une chambre microfluidique, et en le développement d’un réseau de capillaires au niveau des pores interstitiels formés par l’empilement de sphères. Les micro-unités tissulaires sont composées de biopolymères représentatifs de la matrice extracellulaire et contiennent des cellules du tissu d’intérêt. Une couche de cellules endothéliales est développée à la surface de ces microsphères. L’empilement de ces microsphères crée un milieu poreux dans lequel du milieu nutritif est perfusé. Le contrôle de l’écoulement au sein d’une telle structure permet l’application de stimuli physiques influençant l’auto-assemblage des cellules endothéliales en capillaires au sein de l’espace interstitiel de l’empilement.Durant cette thèse, un dispositif de fabrication de microsphères à partir de biopolymères naturels a été développé. La structure formée par les empilements de sphères a été étudiée et les écoulements au sein de tels milieux ont été caractérisés de sorte à appliquer des stimuli physiques contrôlés aux cellules. Un système microfluidique de perfusion, de type bioréacteur, intégrant une chambre de développement a été fabriquée. Une construction tissulaire épaisse a pu être formée au sein de ce système et le développement du réseau vasculaire a été favorisé. La formation du réseau a été montrée par la présence de capillaires sanguins perfusés au sein de la structure. La technique développée promet une application au développement de nombreux tissus et des applications pour des dispositifs d’organes-sur-puces ou d’ingénierie tissulaireTissue engineering aims to develop functional tissues or organs in vitro in order to provide drug testing platforms or transplantable tissues and improve the treatments provided to patients. However, the physiological tissue structures developed to date do not integrate and perfusable vascular network. In vivo, the vascular network supplies the body’s cells with oxygen and nutrients and removes cellular waste and carbon dioxide. It also has a major role in maintaining organ homeostasis. Blood capillaries are hollow vessels whose walls are only composed of a layer of endothelial cells and diffuse nutrients. The blood capillary network is dense and perfuse all tissues. Due to the limit oxygen diffusion inside tissues, each cell is located at most 200µm away from a capillary. The difficulties of building a network of perfusable capillaries and integrating them into tissue constructs limit the development of thick physiological tissues.An innovative technique for developing a microvascular network within a thick construction is presented in this thesis. This technique consists of assembling spherical tissue micro-units within a microfluidic chamber, and developing a network of capillaries through the interstitial pores formed by the spheres packing. Tissue micro-units are composed of biopolymers representative of the extracellular matrix and contain cells from the tissue of interest. A layer of endothelial cells is developed on the surface of these microspheres. The stacking of these microspheres creates a porous medium in which nutrient medium is perfused. Flow control within such a structure allows the application of physical stimuli influencing the self-assembly of endothelial cells into capillaries within the interstitial space of the sphere packing.During this thesis, a device for manufacturing microspheres from natural biopolymers was developed. The structure formed by the stacks of spheres was studied and the flow within such environments were characterized so as to apply controlled physical stimuli to cells. A bioreactor-like perfusion system has been built. A thick tissue structure could be formed within this system and the development of the vascular network was promoted. The formation of the network was demonstrated by the presence of infused blood capillaries within the structure. The technique developed promises to be applied to the development of many tissues and applications for organ-on-chip or tissue engineering devices
39
Saarela, U. (Ulla). "Novel culture and organoid technologies to study mammalian kidney development." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526218250.
Full textAbstract:
Abstract Kidney diseases affect an increasing number of people worldwide, and there is a growing demand to develop new treatments and increase the number of transplantable organs. New treatments can be designed when new knowledge is gained by studying the details of kidney development. The ex vivo culture techniques have been used for over a century to study the development of kidneys, but they are not optimal for long-term imaging and following the nephrogenesis process over time. Kidney organoids, which are cellular aggregates resembling the in vivo kidney, together with intact embryonic kidneys, present a platform for these studies. However, there are limitations when working with primary embryonic kidney cells. Primary embryonic metanephric mesenchymal cells are usually low in number and lose the ability to undergo nephrogenesis rapidly. New ways to culture, biobank, and transfect cells can offer ways for functional testing of the effects of different genes on the nephrogenesis. This study presents new tools for studying nephrogenesis. Time-lapse imaging of organ development may be enhanced by using a Fixed Z-direction (FiZD) culture system where the kidney explant is grown in a restricted 70μm space. The technique enables the segmentation of the individual cells in a two-dimensional image and a dynamic analysis of the time-lapse data. This study also presents a technique of dissociation and reaggregation of the uninduced kidney metanephric mesenchyme (MM). With this novel method of culturing the dissociated MM cells in a growth factor medium for 24 hours, the cells can keep their competence for nephrogenesis. This technique allows the genetic manipulation of the MM cells before the induction to form nephrons, allowing functional testing of genes in the metanephric mesenchyme. This study further presents different techniques for gene editing of MM cells and introduces biobanking of primary kidney cells. It is shown here that the MM and ureteric bud (UB) cells have the capability to remember their fates and build nephron-like structures or continue branching after the cryopreservation in the liquid nitrogen. The methods introduced here provide new ways to create kidney organoids, manipulate their genome, and biobank the primary embryonic kidney cells. The developed FiZD culture system enhances the imaging of kidney development compared to the previously used culture methods. Using this method, the morphogenesis of the developing kidney can be followed more precisely, even in a single cell level. This culture method may also be used to culturing other organs, such as ovary, and may help provide insights into the development of other tissues as wellTiivistelmä Munuaissairauksiin sairastuvien määrä on lisääntynyt maailmanlaajuisesti, ja se on aikaansaanut tarpeen uusien hoitokeinojen sekä siirtoelimien kehitykseen. Näiden kehittämiseksi tarvitsemme uutta tietoa munuaisen kehityksestä ja toiminnasta. Munuaisen kehitystä on tutkittu ex vivo -viljelyn avulla jo yli vuosisadan ajan, mutta nykyiset elinviljelytekniikat eivät ole kuitenkaan optimaalisia pitkäkestoiseen time-lapse-kuvaukseen. Tässä työssä käytetään munuaisen kehityksen tutkimiseen hiiren alkion munuaisia sekä munuaisorganoideja, jotka ovat munuaissoluista koostuvia ja aitoa munuaista mallintavia soluaggregaatteja. Primaaristen munuaissolujen käyttöön sisältyy rajoitteita, ja tämä luo tarpeen uusien organoiditekniikoiden kehitykseen ja optimointiin. Primaarisia munuaissoluja on yleensä käytettävissä pieniä määriä, ja ne eivät myöskään sovellu pitkäkestoiseen kasvatukseen, koska ne menettävät nopeasti kykynsä muodostaa nefroneita. Uusien tekniikoiden avulla voidaan parantaa näiden solujen kasvatusta, säilytystä ja transfektointia ja edistää eri geenien vaikutuksia tutkivat funktionaaliset testaukset. Tässä tutkimuksessa esitetään uusia työkaluja nefrogeneesin tutkimiseen. Elinten kehitystä seuraavan time-lapse-kuvauksen laatua voidaan parantaa käyttämällä tässä työssä esitettyä FiZD-kasvatusmenetelmää, jossa munuaiseksplantti kasvaa rajoitetussa 70μm:n tilassa. Kuvat ovat korkealaatuisia, ja se mahdollistaa 2D-kuvan yksittäisten solujen segmentoinnin ja solujen liikkeiden dynaamisen analyysin. Lisäksi tässä tutkimuksessa esitetään ei-indusoidun munuaismesenkyymin käsittelyyn kehitetty dissosiaatio- ja reaggregaatiomenetelmä. Munuaisen kehityksen alkuvaiheessa on mahdollistaerottaa nefroneja muodostava metanefrinen mesenkyymi (MM) sekä munuaisen kokoajaputkiston muodostava ureterin silmu. Metanefrinen mesenkyymi voidaan hajottaa yksisolususpensioksi, säilyttää 24 tuntia kasvutekijämediumissa ja tämän jälkeen reaggregoida ja indusoida muodostamaan nefroneita. Tämä tekniikka mahdollistaa MM-solujen geneettisen muokkauksen, ennen kuin munuaisen kehitys alkaa. Tämä tekniikka mahdollistaa myös dissosioitujen MM solujen geneettiset muokkaukset. Geenien yliekspression tai hiljentämisen avulla voidaan tehdä funktionaalisia kokeita näiden muutosten vaikutuksesta nefrogeneesiin. Lisäksi tässä työssä esitetään munuaisprogenitorisolujen säilömistä syväjäädytyksellä. Munuaisprogenitorisolut voidaan säilöä nestetyppeen, minkä jälkeen ne ovat edelleen kykeneviä muodostamaan nefronirakenteita tai haarautumaan. Tässä väitöskirjatyössä esitettyjen menetelmien avulla on tulevaisuudessa mahdollista saada lisätietoa munuaisten kehitysprosessista. Kehitetty FiZD-kasvatusmenetelmä parantaa munuaisen kehityksen kuvantamista ja mahdollistaa yksittäisten solujen seuraamisen. Tämä kasvatusmenetelmä sopii myös muiden elinten, kuten munarauhasten, ja kudosten kasvatukseen, ja sen avulla voidaan saada tietoa myös niiden kehityksestä
40
Russ, Jane Hannah. "Use of organ-culture, irradiation and adoptive-transfer to investigate the role of the Xenopus thymus in T lymphocyte development." Thesis, Durham University, 1986. http://etheses.dur.ac.uk/6885/.
Full textAbstract:
This Thesis attempts to develop an amphibian model system for exploring the role of the thymus, particularly its stromal cells, in the acquisition of allotolerance. Inbred, clonal and cytogenetically-marked Xenopus are used in this work. The initial experiments (Chapter 2) describe in vitro attempts to deplete the larval and post-metamorphic thymus of its lymphocyte component, while leaving its stromal elements intact. The histologic effects of deoxyguanosine-treatment and 6 -irradiation on the organ-cultured thymus are examined in wax sections. In vivo whole-body irradiation (3000R) and subsequent in situ residence for ~ 10 days proves the most successful technique for depleting thymic lymphocyte numbers from the froglet thymus (Chapter 3). This technique provides a lymphocyte-depleted thymus with a fairly normal 3-d stromal network. Furthermore, these thymuses show no sign of lymphocyte regeneration when organ-cultured for ~ 2 weeks. In Chapter 3, 1 um sections and electron microscopy of plastic-embedded sections provides a detailed picture of the froglet thymus following irradiation. Chapters 4 and 5 employ ploidy labelling and the X. borealis (quinacrine-fluorescence) cell marker system, to show that larval and adult (normal or in vivo irradiated) thymuses, implanted to early- thymectomized Xenopus (MHC-compatible. or -incompatible), become infiltrated by host lymphoid cells, the thymic epithelium remaining donor-derived. A time-course study shows that for normal thymus implants, host cells begin to immigrate in good number only after metamorphosis is complete; with these thymus implants, donor-derived lymphocytes can still be found in the blood and spleen of thymectomized hosts several months post-implantation. Irradiated thymus implants attracted host cells more rapidly, their lymphoid complement becoming almost exclusively host-type within 2 weeks post-implantation when animals were at a late larval stage of development. Despite rapid colonization of irradiated implants by host lymphoid cells, these thymuses degenerate soon after metamorphosis, presumably due to irradiation damage of stromal elements. The experiments in Chapter 6 compare the proliferative responses of thymocytes from normal and organ-cultured thymuses. The technical conditions (e.g. cell numbers per well) for obtaining good stimulation indices with T cell mitogens, and in mixed leucocyte culture (MLC), are examined. Thymocytes organ-cultured for 12 days generally display elevated 3HTdR uptake compared with cells tested straight from the animal. Both control and experimental (mitogen- or alloantigen-treated) cultures of organ-cultured thymocytes show these elevated DPM. Surprisingly, in vivo-irradiated, organ-cultured thymocytes, are still stimulated by phytohaemagglutinin (PHA)-treatment. Chapter 7 investigates in vitro T-cell proliferative responses of splenocytes and thymocytes in allothymus-implanted, early- thymectomized Xenopus. Splenocyte reactivity to PHA and to third- party alloantigens (in MLC) is restored when normal allogeneic thymus is implanted ("adoptively-transferred"). However, MLC reactivity of thymocytes and splenocytes to thymus-donor strain cells is generally lacking; allothymus-implanted animals are also tolerant to thymus-donor strain skin grafts. Unfortunately, thymectomized animals implanted with in vivo irradiated, allothymuses died prior to in vitro assaying. Preliminary attempts to generate supernatants (by treating cultured splenocytes with PHA and/or phorbol myristate acetate) that would routinely enhance T cell proliferative responses of thymocytes, are outlined in Chapter 8. General conclusions to be drawn from this Thesis and suggestions for future work with this amphibian model are to be found in Chapter 9.
41
Konduri, Suchitra. "The Influence of normal physiological forces on porcine aortic heart valves in a sterile ex-vivo pulsatile organ culture system." Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-03042005-135623/unrestricted/konduri%5Fsuchitra%5F200505%5Fmast.pdf.
Full textAbstract:
Thesis (M. S.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2005.Dr. Athanassios Sambanis, Committee Member ; Dr. Timothy M. Wick, Committee Member ; Dr. Ajit P.Yoganathan, Committee Chair. Includes bibliographical references.
42
Konda, Bikash [Verfasser], and Jutta [Akademischer Betreuer] Engel. "Response of mammalian eye lenses to space radiation qualities in vitro and in organ culture / Bikash Konda ; Betreuer: Jutta Engel." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2019. http://d-nb.info/1205735216/34.
Full text
43
Abdin, Alaa Din [Verfasser]. "Impact of dextran in organ culture media for preservation of DMEK (Descemet Membrane Endothelial Keratoplasty) precut tissue / Alaa Din Abdin." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1216104832/34.
Full text
44
Hreinsson, Julius. "Preservation of fertility through cryopreservation and in vitro maturation of human ovarian follicles and oocytes /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-698-7.
Full text
45
Junttila, S. (Sanna). "Studies of kidney induction in vitro using gene expression profiling and novel tissue manipulation technique." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526206608.
Full textAbstract:
Abstract For decades, the mammalian kidney has served as a model system for studying developmental processes, such as induced epithelialization, branching morphogenesis, and cell differentiations. The possibility to recapitulate and follow the renal organogenesis ex vivo in organ culture set-ups has provided a large amount of molecular and cellular information about sequential events during development. However, certain limitations remain when combining traditional organ culture set-ups with modern molecular technology. This thesis seeks to address these disadvantages. In the experimental part of the thesis, the traditional organ culture set-ups were studied, modified, and optimized to meet the needs of functional genetic screening. First, the traditional transfilter- induced nephrogenesis was characterized with a panel of nephron segment specific markers to reveal the differentiation level of in vitro developing mouse renal tissue. A comprehensive genome wide time course microarray analysis was also performed to in vitro- induced metanephric mesenchyme. Next, to improve the accessibility of genetic tools into the three- dimensional organ in culture, the classic kidney culture set-ups were modified to tolerate dissociation and re-aggregation before the induction of nephrogenesis. This step was achieved with the aid of preservative growth factors offering a 24- hour window to manipulate the genetic and cellular composition of the explant. The dissociation and re-aggregation per se had not particular effect on the progress of the nephron differentiation. Demonstrations of the addition and removal of cells, as well as a virus vector mediated gene knock in and knock down are presented. The gene expression data, together with the novel organ manipulation and culture techniques presented in this thesis, provide a useful guide and specific tools to further characterize the details of nephron development and differentiation in functional mannerTiivistelmä Nisäkkäiden munuainen on toiminut vuosikymmeniä mallielimenä tutkittaessa kehitysbiologisia tapahtumasarjoja, kuten epitelisaatiota, haaroittumismorfologiaa sekä solujen erilaistumista. Munuaisaihioita voidaan viljellä laboratorio-olosuhteissa, jolloin kehityksen aikaisia muutoksia päästään seuraamaan lähes reaaliaikaisesti. Perinteisten kudosviljelytekniikoiden tarjoamat mahdollisuudet solujen molekulaariseen muokkaukseen ovat kuitenkin varsin rajalliset. Tässä väitöskirjassa esitettävät tulokset pyrkivät osaltaan vähentämään näitä rajoitteita. Väitöskirjan kokeellisessa osassa tarkastellaan lähemmin klassista munuaiskudosviljelyä sekä esitetään siihen tehtyjä optimointeja, joiden avulla kudosviljelyä pyritään hyödyntämään geenien toiminnan tutkimuksessa. Aluksi perinteisellä tavalla reikäisen kalvon läpi indusoitu nefroni karakterisoitiin tarkasti hyödyntäen useita erilaistumista osoittavia merkkimolekyylejä. Lisäksi samalla tekniikalla tuotettujen munuaiskudosviljelmien geeniekspressiota tutkittiin mikrosiruanalyysillä. Klassisia kudosviljelytekniikoita muokattiin soveltuvammaksi moderneille geneettisille työkaluille. Munuaiskudos hajotettiin ensin solususpensioksi, jonka jälkeen solut muodostivat uudelleen kolmiulotteisen, kudosmaisen rakenteen. Hyödyntämällä suojaavia kasvutekijöitä, hajotus kyettiin tekemään jo ennen nefronien muodostumisen alkua. Näin saavutettin 24 tunnin aikaikkuna indusoimattoman kudoksen geneettiselle muokkaukselle. Väitöskirjassa esitelläänkin demonsrtaatiot solujen lisäämisestä ja poistamisesta sekä virusvälitteisestä geenin aktivoinnista ja hiljennyksestä hyödyntäen uutta kudosmanipulaatio ja –vilejelytekniikkaa. Nefronin kehityksen aikaisen geeniekspression kartoitus sekä tässä tutkimuksessa kehitetyt uudet kudosmanipulaatio ja -viljelytekniikat tarjoavat yhdessä työkaluja molekyylitason yksityiskohtaiseen tutkimiseen
46
Korecki, Casey. "Effects of Compression Loading, Injury, and Age on Intervertebral Disc Mechanics, Biology and Metabolism Using Large Animal Organ and Cell Culture Systems." ScholarWorks @ UVM, 2008. http://scholarworks.uvm.edu/graddis/126.
Full textAbstract:
The intervertebral disc (IVD) is a complex orthopaedic tissue that is located between the vertebrae in the spine. Degeneration of the IVD is thought to be a contributor to low back pain (LBP), which affects up to 80% of the population at enormous economic cost. The role of the intervertebral disc in supporting and resisting applied loading to the spine, along with the observation of disorders associated with abnormal spinal loading, provide support to the theory that applied mechanical loading is crucial in maintaining the health of the intervertebral disc. The encompassing goal of this work was to examine the biological response of the intervertebral disc to changes in the surrounding mechanical environment in a large animal model. Aim 1 utilized an organ culture model to explore the relationship between disc mechanics and biology in needle puncture injury, a commonly used model of experimentally induced disc degeneration, thus providing a possible mechanism for in vivo injury induced disc degeneration models. Aim 2 was to explore the interaction between the amplitude of applied mechanical loading and intervertebral disc cell signaling, also performed in an organ culture model to include cell-matrix signal transduction. Aim 3 addressed frequency and age effects on the IVD response to mechanical stimulation, performed in vitro to control for the effects of varying matrix compositions between old and young animals. Finally, Aim 4 utilized kmeans and fuzzy c-means clustering techniques to reveal patterns in experimental phenotype (determined by gene expression data) and gene response to experimental conditions. The application of biclustering, where the gene responses within experimental phenotypes are clustered to elucidate possible mechanisms for different gene level-responses to experimental conditions, was also accomplished. Finally, the ability for the model to predict the behavior of other genes critical to IVD mechanobiology, or in determining the membership of an unexamined experimental phenotype was explored. Overall, applied dynamic compression was not found to significantly alter disc mechanics, while a disruption in the annulus through needle puncture rapidly decreased the compressive modulus. Changes in disc mechanics may precede biological remodeling, with little evidence of remodeling present without mechanical alteration. Aging, however, crucially impacts disc cell biology, particularly in the nucleus pulposus, and will interact with applied loading to further impact the ability for the intervertebral disc cells to maintain a healthy extracellular matrix.
47
Das, Pritam. "Membrane micro-structurée utilisable comme support au développement de cellule humaine : développement, caractérisation et interaction cellule-matrice." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30282/document.
Full textAbstract:
Les matériaux à structure tridimensionnelle laissent entrevoir de nombreuses applications prometteuses dans le domaine de l'ingénierie tissulaire et de la médecine régénérative en fournissant un micro-environnement approprié pour l'incorporation de cellules ou de facteurs de croissance afin de régénérer des tissus ou organes endommagés. Dans ce contexte, une membrane a été élaborée à partir d'un mélange de poly (ε-caprolactone) PCL / chitosan CHT à partir d'une technique d'inversion de phase permettant un apport localisé de non solvent. La technique permet d'obtenir une double morphologie poreuse : (i) des macrovides en surface (gros pores) facilement accessibles pour l'invasion et la viabilité des cellules; (ii) un réseau macroporeux interconnecté (petits pores) pour transférer les nutriments, l'oxygène, le facteur de croissance à travers le matériau. Les propriétés physico-chimiques (taille des pores, chimie de surface et biodégradabilité) des matériaux ont été caractérisées. Il est montré comment il est possible d'ajuster les propriétés de la membrane en modifiant le rapport PCL / CHT. Des cultures de cellules souches mésenchymateuses humaines (CSMh) ont été réalisées sur la membrane. La viabilité et la prolifération cellulaires ont été étudiées par des essais de test au MTT et de taux d'absorption d'oxygène. Les expériences démontrent que la membrane est biocompatible et peut être colonisée par les cellules. La microscopie confocale montre que les cellules sont capables de pénétrer à l'intérieur des macrovides de la membrane. La prolifération cellulaire de CSM dans ce matériau pourrait être utile pour augmenter la longévité d'autres cellules primaires en modifiant les CSM pour produire des facteurs de croissance. Pour tester le comportement dynamique des cellules sur la membrane, un dispositif d'organe sur puce a été développé avec des cellules endothéliales ombilicales humaines ensemencées sur la membrane. Les résistances hydrauliques de la barrière cellulaire sur la membrane ont été quantifiées en temps réel pour une pression trans-endothéliale (PTE), 20 cm H2O à 37 ° C et avec des cellules vivantes après 1 jour et 3 jours après l'ensemencement. Les résultats suggèrent que ce type d'échafaudages polymères peut être utile à l'avenir comme patch in vivo pour réparer des vaisseaux endommagésOver the last decades, three-dimensional (3D) scaffolds are unfolding many promising applications in tissue engineering and regenerative medicine field by providing suitable microenvironment for the incorporation of cells or growth factors to regenerate damaged tissues or organs. The three-dimensional polymeric porous scaffolds with higher porosities having homogeneous interconnected pore network are highly useful for tissue engineering. In this context, a poly (ε- caprolactone) PCL/chitosan CHT blend membrane with a double porous morphology was developed by modified liquid induced phase inversion technique. The membrane shows: (i) surface macrovoids (big pores) which could be easily accessible for cells invasion and viability; (ii) interconnected microporous (small pores) network to transfer essential nutrients, oxygen, growth factors between the macrovoids and throughout the scaffolds. The physico-chemical properties (pore size, surface chemistry and biodegradability) of the materials have been characterized. This study shows how it is possible to tune the membrane properties by changing the PCL/CHT ratio. Human mesenchymal stem cell (hMSCs) culture was performed on the membranes and the cell viability and proliferation was investigated by MTT assay and oxygen uptake rate experiments. The experiments demonstrate that the membranes are biocompatible and can be colonized by the cells at micron scale. Confocal microscopy images show that the cells are able to adhere and penetrate inside the macrovoids of the membranes. Both cell proliferation and oxygen uptake increase with time especially on membranes with lower chitosan concentration. The presence of chitosan in the blend produces an increase of porosity that affect the entrapment of the cells inside the porous bulk of the membranes. Successful cellular proliferation of hMSCs could be useful to enhance longevity of other primary cells by production of corresponding growth factors. To test the dynamic behavior of cells on the membranes, an organ-on-chip (OOC) device has been developed with human umbilical endothelial cells (HUVECs) seeded on the membrane. The hydraulic resistance of the cellular barrier on the membrane has been quantified for real time trans-endothelial pressure (TEP) 20 cmH2O at 37 degree C and with living cells after 1 day and 3 day of post seeding. Results suggests this kind of polymeric scaffolds can be useful in future as an in vivo patch to repair disrupted vessels
48
Khidhir, Karzan Ghafur. "Regulation of hair growth : prostaglandins and prostamides : studies confirming the growth stimulating effects of prostanoids and prostamides on human hair follicles in organ culture and locating their receptors using lipidomics, molecular biological and immunohistological approaches." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/5372.
Full textAbstract:
Hair growth disorders cause significant psychological distress, but are poorly controlled. Since prostaglandin F₂α (PGF₂α) and prostamide F₂α analogue glaucoma treatments cause eyelash growth as side-effects, they may be useful for alopecia. How they function is unknown; possibilities include direct action on hair follicles or stimulating follicular blood flow. It is important to clarify whether scalp follicles can also respond as human follicle response to androgens differ with body site. Therefore, human scalp follicles were grown in vitro in organ culture with PGF₂α, latanoprost, a PGF₂α analogue, and bimatoprost, a prostamide F₂α analogue, with, or without, appropriate antagonists, and the presence of PGF₂α (FP) and prostamide F₂α receptors were investigated using molecular biological and immunohiostochemical methods. Each treatment significantly stimulated follicle growth rate, the percentage of growing follicles, and the amount of hair produced in a dose-responsive manner (10nM-1μM); the receptor antagonists blocked these effects. Immunohistochemistry of frozen scalp sections demonstrated FP protein only in dermal papillae and connective tissue sheaths. RT-PCR identified FP and various prostamide F₂α receptors in anagen follicles and isolated dermal papillae and bulbar connective tissue sheath, but not in bulb matrix or other epithelial tissues. Therefore, isolated human scalp hair follicles can respond biologically to PGF₂α and related pharmaceuticals in organ culture via follicular receptors and express the genes and protein for FP and prostamide F₂α receptors. PGF₂α-related drugs appear to act directly on follicles via receptors in the regulatory dermal papilla. They offer an exciting, novel approach for treating alopecia and merit clinical investigation.
49
Castro, Mirna. "Pharmacokinetic studies on protoporphyrin IX induced by 5-aminolevulinic acid and its esters in a three-dimensional lung tumor mini-organ culture model." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-33239.
Full text
50
Becker, Daniel. "At the intersection of the clinic and the laboratory : the invention, dissemination, and application of organ replacement therapy in late-Victorian medical culture." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10627/.
Full textAbstract:
This thesis re-evaluates the initial use of organ replacement therapy in Britain during the 1890s with regard to the thyroid gland and the associated disease entity of myxoedema as paradigmatic examples. The scope of my argument, however, encompasses the period between the 1850s and 1910s, as it approaches this subject from three perspectives. Firstly, this thesis examines the difficult and multifaceted history of thyroid insufficiency disorders between 1850 and 1878, such as endemic cretinism and goitre. Secondly, the introduction of myxoedema as a distinct clinical entity between 1878 and 1888 is discussed. Finally, the professional debates surrounding the new therapeutic approach of organ replacement therapy and its clinical application and scientific assessment are analysed for the period from the 1890s onward. By focussing on the notions of disease causation via key historical figures and their publications, I argue that there was a mutual influence between the conception of myxoedema and organ replacement therapy, and that neither one would otherwise have become acceptable by the standards of late-nineteenth and early-twentieth-century scientific medicine. The origins of the ensemble of the new concepts and practices that constitute myxoedema and the associated organ replacement therapy can thereby be situated within a specific timeframe and context. They did not simply arise from contemporary medical knowledge, nor were they the culmination of some long-held desire of the medical community, or solely the result of medical progress. Instead, the practice of organ replacement therapy, as well as the new disease entity of myxoedema, depended on a view of the human body that assumed the medical possibility and desirability of replacing an organ’s lost function. This view was part of the concept of organ replacement, which emerged in the specific context of an experiment-oriented style of university medicine that predominated in the late nineteenth and early twentieth centuries. Its emergence depended on contemporary clinical and scientific practices as well as on the institutional and epistemological context within which these practices were embedded. As this thesis demonstrates, various social, scientific, and technical conditions needed to concur before organ replacement therapy could become part of medical reality.